His expressed why is that we know there will be more mass extinction causing meteors in Earth's future.
It's just a matter of when.
Maybe we're lucky and it's another 65 million years.
Maybe it's just 65 years.
I wonder sometimes what would have happened if the
Tunguska meteor had come 50 years and a few hours later, and about 5 degrees latitude further south.
That was estimated to be <200 ft in size, and an airburst.
Probably would have heralded nuclear Armageddon bursting over Moscow in 1958.
Tourism will be one way, but there will be people who want to go and stay too. Making and lifting things off Mars will be cheaper than lifting them off Earth as we explore (and harvest) the rest of the solar system.
In time we'll see a lot of the most polluting work 'off-shored' from the planet, and this place will be restored to a more pristine environment.
I think of the robots as just augmentation for human labor. To move the boxes off the rocket, and off the truck. To sweep the floors, and a myriad of other necessary jobs that don't take a big brain. Instead of all human janitors, you'll have one guy controlling dozens, and a tech to fix them.